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Forum: Coders. AMOS 24 July 2019, 17:10
Replies: 5
Views: 651
Posted By adrazar
Here is a more or less complete guide for how to...

Here is a more or less complete guide for how to go about making such a program in AMOS Professional, it's not much work really but it might take some time to figure out each step since you're new to...
Forum: Coders. AMOS 22 July 2019, 15:32
Replies: 5
Views: 651
Posted By adrazar
This code could do as a starting point: ...

This code could do as a starting point:

Print "Press ESCAPE to quit"
Repeat
For KEY=80 To 89
If Key State(KEY)
Print "F"+Str$(KEY-79)-" "
While Key State(KEY) :...
Forum: Coders. AMOS 06 March 2019, 01:28
Replies: 3
Views: 1,109
Posted By adrazar
You're welcome ;)

You're welcome ;)
Forum: Coders. AMOS 05 March 2019, 12:56
Replies: 3
Views: 1,109
Posted By adrazar
Ha! I know this one :D It's Auto View's...

Ha! I know this one :D

It's Auto View's fault; you'll have to turn it off with Auto View Off and add a View right after Screen Offset.
The command View reveals the effect of Screen Open, Screen...
Forum: Coders. AMOS 17 February 2019, 15:32
Replies: 2
Views: 1,118
Posted By adrazar
Colour 1,2,3,... in the Object editor become...

Colour 1,2,3,... in the Object editor become colour 17,18,19,... if the images are used by a sprite. So you will have to customize colour 17-31 to get the colours right for sprites.
(By the way, the...
Forum: Coders. AMOS 15 February 2019, 04:41
Replies: 10
Views: 2,121
Posted By adrazar
Um, forgot to clarify the perhaps greatest source...

Um, forgot to clarify the perhaps greatest source of confusion: the formulas for UPPERHALF and LOWERHALF will not make sense unless the computations are done in binary representation. Division by 128...
Forum: Coders. AMOS 14 February 2019, 22:20
Replies: 10
Views: 2,121
Posted By adrazar
I didn't really explain anything so that's...

I didn't really explain anything so that's probably mostly my fault..
I'll now do the reasonable thing and add the missing explanation :): Note first that each letter represents a bit in an 8x8...
Forum: Coders. AMOS 28 January 2019, 23:11
Replies: 10
Views: 2,121
Posted By adrazar
The book "Hacker's Delight" presents a rather...

The book "Hacker's Delight" presents a rather clever method for transposing "bit-matrices" of size 8x8 bits. Bit matrix transposition can be used for 90-degree rotations too if combined with a...
Forum: Coders. AMOS 27 November 2018, 20:30
Replies: 10
Views: 2,121
Posted By adrazar
Clever thinking! If you are going to do either a...

Clever thinking! If you are going to do either a manual rotation or a colour change anyway, you can actually do both without spending any additional time. :agree

I notice you must be using 16...
Forum: Coders. AMOS 23 November 2018, 15:25
Replies: 10
Views: 2,121
Posted By adrazar
The command Rev() can do 180°-rotations. Hence...

The command Rev() can do 180°-rotations. Hence it's possible to have all four orientations with only two images; one facing U/D and one facing L/R.
There's no command that rotates images 90° on the...
Forum: Coders. AMOS 12 November 2018, 02:59
Replies: 2
Views: 1,564
Posted By adrazar
I'm pretty sure the only way is to read it from...

I'm pretty sure the only way is to read it from the data structure manually. :/

The code looks something like this:

IMGADR=Leek(Start(2)+IMG*8+2)

WIDTH=16*Deek(IMGADR)
HEIGHT=Deek(IMGADR+2)...
Forum: Coders. Asm / Hardware 02 November 2018, 03:33
Replies: 69
Views: 3,439
Posted By adrazar
I didn't proofread 3. properly, and I realise the...

I didn't proofread 3. properly, and I realise the last sentence doesn't make sense in the surrounding context.
I'll take the liberty of editing it a bit ;)

3. is a special case because it says...
Forum: Coders. Asm / Hardware 01 November 2018, 19:49
Replies: 69
Views: 3,439
Posted By adrazar
Things became a lot clearer to me now :) I...

Things became a lot clearer to me now :)
I observed that if (line == EVx) then DMA loads xPOS/xCTL regardless of the channel state.
I used to think xPOS/xCTL reloads would happen only if the sprite...
Forum: Coders. Asm / Hardware 29 October 2018, 18:45
Replies: 69
Views: 3,439
Posted By adrazar
Ok :great About post #26, could you please...

Ok :great

About post #26, could you please double check for me that you really did look at the code there?
The funny thing about it was that DMA got disabled without relying on a DMA-access.

...
Forum: Coders. Asm / Hardware 29 October 2018, 14:53
Replies: 69
Views: 3,439
Posted By adrazar
Almost good now :) Only the last part remain a...

Almost good now :)
Only the last part remain a bit unclear, nice to have it straightened out for the sake of completion ;)

I didn't quite follow this argument the last time you presented it, and...
Forum: Coders. Asm / Hardware 27 October 2018, 21:02
Replies: 69
Views: 3,439
Posted By adrazar
I still fail to see how the current set of rules...

I still fail to see how the current set of rules explains that DMA could be stopped by writing the current line value to SPRxCTL.
It was clear from post #26 that DMA did not load any value into xCTL...
Forum: Coders. Asm / Hardware 27 October 2018, 20:21
Replies: 69
Views: 3,439
Posted By adrazar
Yes, it displays exactly the behaviour I was...

Yes, it displays exactly the behaviour I was referring to. :)
Forum: Coders. Asm / Hardware 27 October 2018, 19:55
Replies: 69
Views: 3,439
Posted By adrazar
Thank you ross :) So the picture shows that...

Thank you ross :)

So the picture shows that writing to xCTL disarmed the sprite because a line is missing.
But DMA is still active because it continues drawing the following lines.
Forum: Coders. Asm / Hardware 27 October 2018, 19:18
Replies: 69
Views: 3,439
Posted By adrazar
Ok, take your previous program and wait for the...

Ok, take your previous program and wait for the middle line of sprite 2, with a horizontal position right after the sprite DMA slots (pixel 128?). Write 0 to SPR2CTL.
Forum: Coders. Asm / Hardware 27 October 2018, 18:49
Replies: 69
Views: 3,439
Posted By adrazar
No, I wrote 0 to SPRxCTL about ten pixels down a...

No, I wrote 0 to SPRxCTL about ten pixels down a sprite and did not touch SPRxPOS. Hence the start position can't have matched the line.

I should probably attach a small program to support my...
Forum: Coders. Asm / Hardware 27 October 2018, 14:35
Replies: 69
Views: 3,439
Posted By adrazar
This the thing :) ...but is the last statement...

This the thing :) ...but is the last statement true?
It's giving the impression you can stop DMA by writing 0 to SPRxCTL, but that's been shown not to be the case.
I also notice a slight lack of...
Forum: Coders. Asm / Hardware 27 October 2018, 03:18
Replies: 69
Views: 3,439
Posted By adrazar
If my treatment in the previous post turned out...

If my treatment in the previous post turned out inadequate, just ignore it.
The main thing at this point would in any case be to identify the actual and complete conditions that must be fulfilled in...
Forum: Coders. Asm / Hardware 27 October 2018, 02:54
Replies: 69
Views: 3,439
Posted By adrazar
That was a very good explanation, and a very...

That was a very good explanation, and a very useful tool for debugging my misconceptions :D
Everything you wrote was in accordance with my former understanding of the matter, except one thing that...
Forum: Coders. Asm / Hardware 26 October 2018, 21:56
Replies: 69
Views: 3,439
Posted By adrazar
!! Here you go ross and Toni, a token of my...

!!
Here you go ross and Toni, a token of my appreciation: :bowdown

Maybe what I've said earlier becomes clearer if I emphasise that I consider 'arming/disarming a sprite' and 'start/stop sprite...
Forum: Coders. Asm / Hardware 26 October 2018, 14:54
Replies: 69
Views: 3,439
Posted By adrazar
So the enabling/disabling of sprite DMA fetches...

So the enabling/disabling of sprite DMA fetches happens continuously and independently of the sprite DMA slots? Then how come the final xPOS/xCTL DMA fetch can happen, when the DMA fetching should...
Forum: Coders. Asm / Hardware 26 October 2018, 13:24
Replies: 69
Views: 3,439
Posted By adrazar
Here is an illustration of what I'm trying to...

Here is an illustration of what I'm trying to achieve, hopefully it clarifies my intentions:
Crude illustration of my display:
+--------------------------------+
| DMA |...
Forum: Coders. Asm / Hardware 26 October 2018, 02:32
Replies: 69
Views: 3,439
Posted By adrazar
Hello again! :) First, thank you all for the...

Hello again! :)

First, thank you all for the replies. It's been a week since I started this thread now, and the time is probably overripe for this, but I hereby confess that still I don't see how...
Forum: Coders. Asm / Hardware 18 October 2018, 15:33
Replies: 69
Views: 3,439
Posted By adrazar
All right, so now we have established that sprite...

All right, so now we have established that sprite DMA fetches may be disabled by having the sprite reach the vertical stop position. But can it be done before somehow, i.e. without having to go...
Forum: Coders. Asm / Hardware 18 October 2018, 14:39
Replies: 69
Views: 3,439
Posted By adrazar
Agree! :agree

Agree! :agree
Forum: Coders. Asm / Hardware 18 October 2018, 14:27
Replies: 69
Views: 3,439
Posted By adrazar
So there should be no more DMA fetches if I set...

So there should be no more DMA fetches if I set EVx = 0, because the while condition wouldn't be satisfied? I tried doing that just now by writing 0 to SPRxCTL, but no, it didn't work... :/
Forum: Coders. Asm / Hardware 18 October 2018, 13:00
Replies: 69
Views: 3,439
Posted By adrazar
I take it you suggest that xDAT is loaded if and...

I take it you suggest that xDAT is loaded if and only if

SV <= beam y < EV,

and that xPOS/xCTL is loaded if and only if

beam y = EV.

I get a different picture:
xDAT is loaded if and only...
Forum: Coders. Asm / Hardware 18 October 2018, 01:42
Replies: 69
Views: 3,439
Posted By adrazar
If I write to SPRxCTL somewhere between the...

If I write to SPRxCTL somewhere between the sprite's DMA slots and its horizontal screen position, that line of the sprite is omitted. The next lines of the sprite are still being displayed however....
Forum: Coders. Asm / Hardware 17 October 2018, 23:26
Replies: 69
Views: 3,439
Posted By adrazar
Really? That seem to work for me only when the...

Really? That seem to work for me only when the sprite is already in manual mode. :shocked
Forum: Coders. Asm / Hardware 17 October 2018, 17:32
Replies: 69
Views: 3,439
Posted By adrazar
How to terminate a sprite in automatic mode?

Hi!

Is it possible to manually turn off automatic data fetching for a sprite channel before it reaches the vertical stop position? I'm missing a control bit for this, does there happen to be one?
Forum: Coders. AMOS 20 April 2018, 15:58
Replies: 6
Views: 2,040
Posted By adrazar
This sounds like a fun challenge! I would like to...

This sounds like a fun challenge! I would like to give it a try, but could use some additional technical info first:
1. How many colours (i.e. bitplanes) does the bobs use?
2. How many colours does...
Forum: Coders. AMOS 02 February 2018, 02:10
Replies: 17
Views: 7,063
Posted By adrazar
This is a way to make Bobsprite Col work on a...

This is a way to make Bobsprite Col work on a scrolling screen (assuming Bob Update has been turned off): Move the bob with the following instruction

Bob N,X Bob(N)-XOFFSET,Y Bob(N)-YOFFSET,
...
Forum: Coders. Asm / Hardware 04 January 2018, 20:29
Replies: 9
Views: 3,118
Posted By adrazar
You got it! The pipelining thing explains it all,...

You got it! The pipelining thing explains it all, thank you :)
Forum: Coders. Asm / Hardware 04 January 2018, 04:22
Replies: 9
Views: 3,118
Posted By adrazar
This thread describes no less than exactly what I...

This thread describes no less than exactly what I have been dabbling with lately, but after reading it I still fail to see why such a blit can't be done...!

To make it dead simple, let's say we...
Forum: Coders. AMOS 30 June 2017, 17:35
Replies: 15
Views: 2,974
Posted By adrazar
Good news! Turns out there is an easy way to...

Good news! Turns out there is an easy way to prevent AMOS from clipping bobs along the horizontal edges (at least for the simple testing program I made):

Doke Screen Base+76,NEW_SCREEN_WIDTH

By...
Forum: Coders. AMOS 22 June 2017, 16:26
Replies: 15
Views: 2,974
Posted By adrazar
I'm trying to make a horizontal scroller, which...

I'm trying to make a horizontal scroller, which means I don't require any vertical copper splitting. But your expert tip for handling bobs in this case is gratefully accepted :) Although, I probably...
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